The effect of no visible smoke dust is achieved through deeply analyzing the more serious emission of smoke dust after transform the unorganized emission of 1^# and 2^# coke ovens of Baotou Steel Qinghua Coal Chemical Engineering Co., Ltd. as well as transforming equipment and facilities of coal car and relevant equipment of gas export system, which is with a certain reference value to transform unorganized emission of tamping coke oven as well as control fugitive emission of smoke dust in the coaling process of tamping coke oven.

The gas flow distribution and gas utilization rate are improved by optimizing the charging system as well as adjusting the material layer thickness of coke and ore aiming at the long-term higher fuel ratio of 5^# blast furnace of Baotou Steel; the smelting is strengthened by such measures as increasing furnace top pressure, hot air temperature and oxygen enrichment rate; meanwhile, the efficiency of tapping iron in front of furnace is improved, daily operations of blast furnace are strengthened and standard work is carried out so that the target of increasing production and reducing consumption is realized. The fuel ratio of 5^# blast furnace reduced from 598.73 kg/t on average in 2020 to 556.9 kg/t, which was the best level in history.

According to the smelting process of converter, the heat balance of converter is calculated with the heat balance calculation method. The influences of different molten iron conditions, production processes and temperature control on improving the addition of scrap steel are calculated. The specific measures for improving the scrap ratio of basic oxygen furnace(BOF) are put forward by analyzing the factors affecting change of scrap ratio of BOF as well as studying the relations between scrap ratio and smelting process conditions of BOF, which are as references for relevant steelmaking plants.

The large-grained ribbed Al₂O₃ inclusion is the main cause of cracking through analyzing the cracking in process of stamping beam steel BT700L. In order to improve the size and morphology of inclusion in product, the rare earth Ce is added in production of beam steel BT700L. Since the affinity of rare earth Ce and oxygen is very strong, the rare earth Ce in molten steel reacts with oxygen and generates rare earth oxide (RE₂O₃) coming up to slag so that the yield of rare earth Ce in steel is extremely low. It could be improved effectively through optimizing and controlling the content of Ce in molten steel of steelmaking and continuous casting, oxidability of slag as well as such process as protective casting of continuous caster. Moreover, the atomic radius of rare earth Ce is greater than that of iron atom and rare earth Ce could denature inclusions in steel. It is found that the size of inclusion in product becomes small, morphology of inclusion spheroidizes and low temperature impacting property of product is effectively improved after add rare earth Ce into molten steel through studying and analyzing adding rare earth Ce into beam steel BT700L.

The 550 MPa grade hot rolled axle housing test steel is rolled in laboratory with the design of medium carbon content+micro alloy Nb and Ti as well as controlled rolling and controlled cooling process. The results showed that the effects of adding moderate rare earth Ce into test steel on its microstructure and strength were not obvious, rare earth Ce reduced the grade of inclusion (class B) in test steel, low temperature impact energy of test steel with rare earth was obviously better than that of test steel without rare earth and fatigue property of axle housing test steel was improved by rare earth Ce.

The hot bends are important components of oil and gas transmission pipeline, so the research and development of hot rolled band for L415M hot bends are with important significances. The band is with low carbon and microalloyed composition of Nb-Ti-Mo, high cleanliness smelting as well as reasonable controlled rolling and controlled cooling process, so it is with excellent comprehensive properties, its microstructure is fine and uniform ferrite and pearlite and their grain size is grade 12.0 as well as the inclusion control is good. Its dimensional accuracy is high as well as surface quality and strip shape are good. After the band is manufactured to hot bends, their overall performances are excellent so that they could meet the operating requirements of users. As a result, the bulk sales and successful applications are realized as well as product quality is well appraised by users.

The 800 MPa grade hydropower engineering steel with low welding crack sensibility is developed through smelting test steel with 100 kg vacuum induction furnace as well as thermal mechanical control processing (TMCP), quenching and tempering processes adopting the alloy system route of low carbon, carbon equivalent (Ceq) and welding crack sensibility index (Pcm) in laboratory. Such mechanical properties as the strength, impact and bending of test steel are tested as well as its microstructure and fracture morphology are analyzed with the optical microscope (OM) and field emission scanning electron microscope (SEM). The results showed that its microstructure at room temperature was tempered sorbite, all its mechanical properties were excellent, its yield strength, tensile strength and elongation after fracture were 788 MPa, 842 MPa and 18.1%, low temperature impact absorbing energy at -40 ℃ was 197 J, strength and toughness well matched as well as welding crack sensitivity index was low, which could meet the performance requirements in use.

In this paper, the causes of cracks are analyzed with the macro morphological observation, chemical composition analysis, metallographic microstructure inspection, scanning electron microscopy and energy spectrum analysis aiming at the surface cracks of H beam web of a large domestic steel plant. The results showed that there was decarburization in the microstructure near cracks as well as there were secondary oxide particles containing silicon and manganese and the characteristic element sodium near matrix, which indicate that the cracks are generated during continuous casting of casting blank and finally formed on the surface of web.

The requirements of non-chrome passivation film for galvanized home appliance plate are mainly focused on such aspects as corrosion resistance, stamping and powder injection performance. In this paper, it is mainly introduced the influences of film weight on the corrosion resistance of non-chrome passivation steel plate, influences of powder injection process parameters on adhesion of powder as well as dynamic friction coefficients of non-chrome passivation products with different compositions and their main applications. In order to achieve good effects, strict control is required in the process of industrial production and end use.

The material characteristics of seamless pipe for 850 MPa drill pipe of rotary drilling rig manufactured by Baotou Steel Tube Co., Ltd. such as mechanical properties, microstructure, ductile-brittle transition temperature, torsional strength and bending fatigue are tested and analyzed. The results showed that its such technical indexes as the mechanical properties, content of nonmetallic inclusions, grades of grain size and banded segregation could all satisfy the requirements of applying 850 MPa high strength and high toughness drill pipe of rotary drilling rig. Moreover, it is with such advantages as low ductile-brittle transition temperature, high torsional strength and good resistance to bending fatigue.